MAX6675 temperature code working, still playing with heater output, other fixes

mendel/Makefile

@@ -36,8 +36,8 @@ CC = $(ARCH)gcc
 OBJDUMP = $(ARCH)objdump
 OBJCOPY = $(ARCH)objcopy
 
-# OPTIMIZE = -Os -ffunction-sections  -finline-functions-called-once -DDEBUG=1
+OPTIMIZE = -Os -ffunction-sections  -finline-functions-called-once -DDEBUG=1
-OPTIMIZE = -O0
+# OPTIMIZE = -O0
 CFLAGS = -g -Wall -Wstrict-prototypes $(OPTIMIZE) -mmcu=$(MCU_TARGET) -DF_CPU=$(F_CPU) $(DEFS) -std=gnu99 -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -save-temps
 LDFLAGS = -Wl,--as-needed -Wl,--gc-sections
 

mendel/gcode.c

@@ -444,6 +444,8 @@ void process_gcode_command(GCODE_COMMAND *gcmd) {
 			// M104- set temperature
 			case 104:
 				temp_set(gcmd->S);
+				enable_heater();
+				enable_steppers();
 				break;
 
 			// M105- get temperature

mendel/mendel.c

@@ -36,13 +36,15 @@ inline void io_init(void) {
 	WRITE(E_STEP_PIN, 0);	SET_OUTPUT(E_STEP_PIN);
 	WRITE(E_DIR_PIN,  0);	SET_OUTPUT(E_DIR_PIN);
 
-	// setup PWM timer: phase-correct PWM, no prescaler, no outputs enabled yet
-	TCCR0A = MASK(WGM00);
-	TCCR0B = MASK(CS00);
-	TIMSK0 = 0;
-
 	#ifdef	HEATER_PIN
-		disable_heater();
+		WRITE(HEATER_PIN, 0); SET_OUTPUT(HEATER_PIN);
+		#ifdef	HEATER_PWM
+			// setup PWM timer: fast PWM, no prescaler
+			OCR0A = 0;
+			TCCR0A = MASK(COM0A1) | MASK(WGM01) | MASK(WGM00);
+			TCCR0B = MASK(CS00);
+			TIMSK0 = 0;
+		#endif
 	#endif
 
 	#ifdef	FAN_PIN
@@ -53,12 +55,13 @@ inline void io_init(void) {
 		disable_steppers();
 	#endif
 
-	WRITE(SCK, 1);				SET_OUTPUT(SCK);
+	WRITE(SCK, 0);				SET_OUTPUT(SCK);
 	WRITE(MISO, 1);				SET_INPUT(MISO);
-	WRITE(SS, 0);					SET_OUTPUT(SS);
+	WRITE(SS, 1);					SET_OUTPUT(SS);
 }
 
-inline void init(void) {
+inline void init(void);
+inline void init() {
 	// set up serial
 	serial_init();
 
@@ -87,8 +90,10 @@ void clock_250ms(void);
 void clock_250ms() {
 	temp_tick();
 
-	if (steptimeout > (30 * 4))
+	if (steptimeout > (30 * 4)) {
-		disable_steppers();
+		if (temp_get_target() == 0)
+			disable_steppers();
+	}
 	else
 		steptimeout++;
 

mendel/pinout.h

@@ -48,7 +48,7 @@
 // OC2B											DIO3
 
 #define	HEATER_PIN					DIO6
-#define	HEATER_PIN_PWM			OC0A
+#define	HEATER_PWM					OCR0A
 
 // #define	FAN_PIN							DIO5
 // #define	FAN_PIN_PWM					OC0B
@@ -107,12 +107,12 @@
 	Heater
 */
 
-#ifdef	HEATER_PIN_PWM
+#ifdef	HEATER_PWM
-	#define	enable_heater()			WRITE(HEATER_PIN, 1)
+	#define	enable_heater()			do { OCR0A = 255; } while (0)
-	#define	disable_heater()		do { WRITE(HEATER_PIN, 0); } while (0)
+	#define	disable_heater()		do { OCR0A = 0; } while (0)
 #else
-	#define	enable_heater()			do { TCCR0A = (TCCR0A & MASK(COM0A0)) | MASK(COM0A1); SET_OUTPUT(HEATER_PIN);  } while (0)
+	#define	enable_heater()			WRITE(HEATER_PIN, 1)
-	#define	disable_heater()		do { WRITE(HEATER_PIN, 0); HEATER_PIN_PWM = 0; TCCR0A &= ~(MASK(COM0A0) | MASK(COM0A1)); SET_OUTPUT(HEATER_PIN); } while (0)
+	#define	disable_heater()		WRITE(HEATER_PIN, 0)
 #endif
 
 /*

mendel/temp.c

@@ -23,6 +23,7 @@
 #include	"clock.h"
 #include	"serial.h"
 #include	"sermsg.h"
+#include	"timer.h"
 
 uint16_t	current_temp = 0;
 uint16_t	target_temp  = 0;
@@ -41,21 +42,37 @@ uint8_t		temp_flags		= 0;
 
 uint16_t temp_read() {
 	uint16_t temp;
-	SPCR = MASK(MSTR) | MASK(SPE);
 
-	WRITE(SS, 1);
+/*	if (DEBUG)
+		serial_writestr_P(PSTR("T["));*/
+
+	// very slow for debugging
+	SPCR = MASK(MSTR) | MASK(SPE) | MASK(SPR1) | MASK(SPR0);
+
+	WRITE(SS, 0);
+
+	delay(1);
 
 	SPDR = 0;
 	for (;(SPSR & MASK(SPIF)) == 0;);
-	temp = SPDR << 8;
+	temp = SPDR;
+
+// 	if (DEBUG)
+// 		serwrite_hex8(temp & 0xFF);
+
+	temp <<= 8;
 
 	SPDR = 0;
 	for (;(SPSR & MASK(SPIF)) == 0;);
 	temp |= SPDR;
 
-	WRITE(SS, 0);
+// 	if (DEBUG)
+// 		serwrite_hex8(temp & 0xFF);
 
-	SPCR = 0;
+	WRITE(SS, 1);
+
+	// turn off SPI system
+// 	SPCR = 0;
 
 	temp_flags = 0;
 	if ((temp & 0x8002) == 0) {
@@ -71,6 +88,9 @@ uint16_t temp_read() {
 		}
 	}
 
+// 	if (DEBUG)
+// 		serial_writechar(']');
+
 	return 0;
 }
 
@@ -82,6 +102,10 @@ uint16_t temp_get() {
 	return current_temp;
 }
 
+uint16_t temp_get_target() {
+	return target_temp;
+}
+
 uint8_t	temp_achieved() {
 	if (current_temp >= target_temp)
 		if ((current_temp - target_temp) < TEMP_HYSTERESIS)
@@ -98,7 +122,18 @@ void temp_print() {
 		serial_writestr_P(PSTR("no thermocouple!"));
 	}
 	else {
-		serwrite_uint16(temp_get());
+		serwrite_uint16(temp_get() >> 2);
+		serial_writechar('.');
+		if (current_temp) {
+			if ((current_temp & 3) == 3)
+				serial_writechar('7');
+			else if ((current_temp & 3) == 1)
+				serial_writechar('2');
+			serial_writechar('5');
+		}
+		else {
+			serial_writechar('0');
+		}
 		serial_writestr_P(PSTR("°C"));
 	}
 	serial_writechar('\n');
@@ -108,8 +143,16 @@ void temp_tick() {
 	uint16_t last_temp = current_temp;
 	temp_read();
 
+	if (DEBUG)
+		serial_writestr_P(PSTR("T{"));
+
 	int16_t	t_error = target_temp - current_temp;
 
+	if (DEBUG) {
+		serial_writestr_P(PSTR("E:"));
+		serwrite_int16(t_error);
+	}
+
 	// PID stuff
 	// proportional
 	heater_p = t_error;
@@ -144,8 +187,13 @@ void temp_tick() {
 	else
 		pid_output = (pid_output_intermed + 128);
 
-#ifdef	HEATER_PIN_PWMABLE
+	if (DEBUG) {
-	HEATER_PIN_PWMABLE = pid_output
+		serial_writestr_P(PSTR("O:"));
+		serwrite_uint8(pid_output);
+	}
+
+#ifdef	HEATER_PWM
+	HEATER_PWM = pid_output;
 #else
 	if (pid_output >= 128) {
 		enable_heater();
@@ -154,4 +202,7 @@ void temp_tick() {
 		disable_heater();
 	}
 #endif
+
+	if (DEBUG)
+		serial_writechar('}');
 }

mendel/temp.h

@@ -12,6 +12,20 @@ extern int32_t d_factor;
 #define		PID_SCALE			1024L
 #define		I_LIMIT				4000
 
+typedef union {
+	struct {
+		uint8_t				high;
+		uint8_t				low;
+	} buf;
+	struct {
+		uint16_t			dummy				:1;
+		uint16_t			reading			:12;
+		uint16_t			tc_open			:1;
+		uint16_t			device_id		:1;
+		uint16_t			tristate		:1;
+	} interpret;
+} max6675_data_format;
+
 // read temperature from sensor
 uint16_t temp_read(void);
 
@@ -21,6 +35,9 @@ void temp_set(uint16_t t);
 // return last read temperature
 uint16_t temp_get(void);
 
+// return target temperature
+uint16_t temp_get_target(void);
+
 // true if last read temp is close to target temp, false otherwise
 uint8_t	temp_achieved(void);